1. Field of the Invention
The present invention relates to an endoscope apparatus including an operation unit operable in a plurality of grasping modes.
2. Description of the Related Art
In general, the operation unit (endoscope body) of an endoscope apparatus is grasped by one hand of an operator, and forceps are operated by the other hand. This operation unit is usually grasped and held by, for example, the left hand, and a curving operation lever to perform a curving operation of the insertion section and switches to supply and suck water are arranged at positions where each finger of the left hand reaches. Usually, an operator bends the left arm to raise the operation unit from the chest to the shoulders, and supports the halfway portion of an elongated insertion section extending downward from the operation unit by the right hand to change the insertion section toward the horizontal direction and insert it into an insertion opening located horizontally.
As for the ordinary operation unit, Jpn. Pat. Appln. KOKAI Publication No. 2009-189685 (patent literature 1) proposes a gun-shaped (L-shaped) operation unit whose insertion section extends in the horizontal direction. This operation unit has a grip portion to be gripped, and the insertion section extends in the horizontal direction from the front.
The operation unit has a proximal end at its lower portion and the insertion section extends downward. Because of this structure, it is difficult for an operator to perform an insertion operation unless the operator stands up to raise the operation unit to a level higher than the chest.
In contrast, the gun-shaped (L-shaped) operation unit of Jpn. Pat. Appln. KOKAI Publication No. 2009-189685 (patent literature 1) includes a grasping section and a front section that overhangs toward the front from an upper portion of the grasping section. The front section is provided with a proximal end of the insertion section, and the insertion section extends in the horizontal direction. With this structure, an operator can perform an inserting operation without standing up. On the other hand, in the conventional operation unit, when an operator tries to insert the insertion section in the horizontal direction, the operator has to take an uncomfortable posture such as that he or she rotates his or her wrist and raises the operation unit on his or her shoulder. The conventional operation unit is not favorable in terms of operability.
The conventional operation unit has a curving mechanism in which a curving portion extends only in the up and down direction. When an operator makes an observation in the right and left direction, he or she has to rotate the operation unit, e.g. 90° around the axis of the insertion section to change a direction in which the insertion section is curved. The insertion section extends downward from the operation unit and is always used in the curved state. Thus, even though the operation unit is rotated 90°, the rotation is attenuated due to a deformation and the distal end of the insertion section is not always rotated 90°. In actuality, therefore, an operator sometimes rotates, more than necessary, the wrist of a hand with which the operator grasps the operation unit. If, furthermore, the insertion section is bent, it is assumed that the intrinsic torque follow-up and curving performance of the insertion section cannot be improved sufficiently due to a loss of the driving force transmission mechanism (e.g. wire and a pully) in the insertion section.
An embodiment of the present invention provides an endoscope including an operation unit which can be grasped in a plurality of modes as desired by an operator and which can be operated comfortably irrespective of an operator's grasping posture.